IT starts with a glimmer in the sky – just a pinprick of light, barely distinguishable from the stars.
But this is no distant celestial body – this is a massive 2,560-foot-wide asteroid heading straight for Earth.
What would happen if a giant asteroid smashed into Earth?[/caption]
London would be completely obliterated[/caption]
The rock is roughly the size of Didymos, a double asteroid system studied by NASA‘s asteroid deflection experiments.
At first, scientists believed it would be a near-miss — a cosmic bullet skimming past without harm.
But the calculations have changed and the probability of impact, once considered remote, is now dangerously real.
And the UK is directly in the firing line.
Now, governments scramble and world leaders hold emergency meetings.
Some suggest a nuclear strike to deflect it, reminiscent of Hollywood disaster films, but the logistics are near-impossible.
Even a direct hit from the world’s most powerful bomb would barely scratch the surface of this cosmic beast.
There’s no time. There’s no way out.
Earth is in the asteroid’s crosshairs. And now, there is nothing left to do but watch…
While the chances of this apocalyptic scenario playing out are near impossible, a new asteroid, 2024 YR4, has sparked concern among space scientists.
The rock, discovered shortly after Christmas last year, has an estimated 2.6% chance of collision with our planet on December 22, 2032, according to NASA.
The asteroid, measuring approximately 40 to 90 meters in diameter, could release energy equivalent to nearly eight megatons of TNT upon impact, enough to devastate a city.
The potential impact zone spans from the eastern Pacific Ocean to southern Asia, posing risks to major cities like Bogotá, Lagos, and Mumbai.
NASA, along with international space agencies, is actively monitoring 2024 YR4 and developing potential mitigation strategies, which might involve deploying a spacecraft to alter the asteroid’s path if necessary.
But it’s not the first time space experts have been faced with a huge asteroid lurking in space – back in 1996 scientists spotted the space rock Didymos, meaning the “God of Chaos”.
Didymos itself was not deflected by NASA’s DART mission as it is not a threat to Earth, but its moon Dimorphos’ orbit was.
This was the first time humans intentionally changed the motion of a celestial object.
Based on interviews with space experts and research on Didymos’ destruction capacity, The Sun takes a look at what an asteroid strike could look like if a space rock as big as Didymos were to hit – with London being ground zero.
T-minus 60 minutes: The world holds its breath
With an hour to go, panic spreads like wildfire.
The UK grinds to a standstill.
Motorways out of London are gridlocked as millions attempt to flee.
The M25 becomes a car park, packed with desperate drivers, horns blaring in a symphony of fear.
Emergency broadcasts cut through television programmes, with the Prime Minister urging people to “seek shelter immediately”.
In central London – one of the projected impact zones – families abandon their homes, rushing out of London, their cars packed with hastily grabbed belongings.
But where can they go? There is no safe zone.
Across Britain, some pray, others riot.
Looters smash their way into supermarkets in a frenzy of desperation.
Meanwhile, social media is flooded with live streams as people document history in real-time, their cameras pointed at the burning streak in the sky.
At the Greenwich Observatory, astronomers sit frozen, their eyes locked onto screens.
They already know what is coming.
Professor Gareth Collins of Imperial College London warns that an impact from an asteroid of this size would carve a permanent crater over 7 miles (11 km) wide and more than 2,000 feet (619 m) deep.
But it’s not just the crater that will kill.
The force of impact will trigger a 7.4-magnitude earthquake, powerful enough to level buildings as far as Birmingham, Collins told Space.com.
The blast wave will shatter windows over 1,000 miles (1,600 km) away— glass will rain down on Paris, Amsterdam, and even Berlin.
And the death toll will be measured not in thousands, but in millions.
Heat effect is one of the primary hazards associated with asteroid impacts, capable of causing widespread fires[/caption]
Not even a direct hit from the world’s most powerful bomb would stop this giant rock from hitting Earth[/caption]
T-minus 30 Minutes: the sky begins to burn
The first sign of disaster is not impact – but fire.
Just like Didymos, the asteroid tears into Earth’s atmosphere at over 40,000mph, the air ahead of it superheating into thousands of degrees.
The sky over the UK turns into a blinding inferno of orange and red as a searing tail of flame stretches for miles behind the rock.
Rooftops are ablaze as the intense heat generated by an asteroid’s atmospheric entry and impact can ignite fires.
A study by the American Geophysical Union says the heat effect is one of the primary hazards associated with asteroid impacts, capable of causing widespread fires over large areas.
The asteroid’s speed also sees windows rattle, car alarms blaring and the Thames trembling at its banks.
That’s because an asteroid travelling at such high speeds would produce a powerful shock wave when entering the atmosphere.
These tremors can shatter windows over vast distances; for instance, the Chelyabinsk meteor’s shockwave broke windows up to 58 miles away, NASA scientists revealed.
In the impact zone, birds scream and scatter, their instincts screaming of the coming doom.
In Buckingham Palace, the lights go out as energy is cut off.
T-Minus 10 Minutes: the Earth trembles
Though it has not yet made contact, the asteroid is already changing the planet.
Tsunami warnings blare across Europe, with seaside towns bracing for potential catastrophe.
The impact of an asteroid on the ocean can create tsunamis that can damage coastal areas depending on the size of the asteroid, says a report published on ScienceDirect.
And if the asteroid is nearly the size of Didymos – a diameter of approximately 780 meters – it is large enough that if it were to impact an ocean, it could generate a significant tsunami.
If the asteroid were to strike deep in the ocean, some of the energy might dissipate.
But if it lands in shallow waters, the tsunami waves could reach the height of skyscrapers.
In Paris, the ground quivers with unseen tremors, as if the Earth itself is bracing for what’s to come.
The fireball in the sky is not only visible but is dominating the heavens.
In central London, the glass panels of The Shard shatter under the unbearable heat and shock waves, as an asteroid of this size striking Earth releases an immense amount of energy, comparable to tonnes of nuclear bombs.
Skyscrapers groan. Bridges buckle.
People in the asteroid’s path stare upward, frozen in place, their final moments slipping away.
T-Minus 1 minute: the final moments
The asteroid is no longer a distant object in the sky. It is the sky.
In London, the land is cast in an eerie twilight, an unnatural shadow as the monstrous rock blocks out the sun.
Winds roar at hurricane speeds, ripping trees from their roots and sending debris spiralling through the air.
The heat is now unbearable as the flaming rock is dangerously close.
And then —
Impact.
The impact wave would shatter windows over 1,000 miles (1,600 km) away[/caption]
A pulse of unimaginable energy would surge through the ground, shaking the UK to its foundations[/caption]
Zero hour: Earth shatters
The asteroid smashes into London with a force of millions of nuclear bombs.
The explosion vaporises everything in a 30-mile radius — Crawley, Slough, Luton, all gone in an instant.
A pulse of unimaginable energy surges through the ground, shaking the UK to its very foundations.
The shockwave detonates outward. London is flattened within seconds. The Houses of Parliament crumble, Big Ben topples like a fallen tree, and Tower Bridge is reduced to rubble in an instant.
Oxford and Cambridge—centuries of history—are obliterated.
The air pressure wave expands outward, shattering windows in France and even the Netherlands.
In Salisbury, Stonehenge buckles before collapsing into dust.
The Earth itself rings like a bell.
A potential asteroid blast could lead to world infrastructure collapsing[/caption]
Electricity grids would fail, hospitals overwhelmed, and diseases would run rampant[/caption]
The aftermath
Following the asteroid’s catastrophic impact, humanity faces the nightmare of survival.
The UK, devastated by the blast, becomes a barren wasteland.
As food supplies dwindle, famine spreads—supermarket shelves empty, and desperate survivors fight for scraps.
The world’s infrastructure collapses — electricity grids fail, hospitals are overwhelmed, and disease runs rampant, with no medicine to stop it.
Societies break down into chaos, with gangs looting and governments powerless.
A brutal winter sets in as ash chokes the sky, plunging temperatures worldwide and freezing crops.
In cities, survivors are surprisingly still able to breathe, but they face hunger, disease, and the constant fear of death.
Capitals like Paris and Berlin lie in ruins, while what’s left of humanity scavenges in the wasteland.
Over time, knowledge and civilisation are lost, leaving only the brutal struggle for survival.
With no hope of recovery, the Earth is left to its own slow, grim decay.
What is Didymos?
THE Didymos asteroid is a double asteroid system, meaning it has two parts.
The larger one is called Didymos, and the smaller one is called Dimorphos.
These two asteroids orbit each other, with Dimorphos being around 160 metres wide (525ft) and Didymos about 780 metres (2559ft) and made of rock and metal.
Scientists are studying it because it is one of the targets for asteroid deflection experiments, like NASA’s DART mission, which crashed a spacecraft into Dimorphos in 2022 to see if they could change its path.
Didymos and Dimorphos orbit the Sun in the asteroid belt, but they are near Earth’s orbit, making them an interesting target for planetary defense research.
While Didymos itself is not a threat to Earth, it is a good example of how to study larger objects that might pose a risk in the future.
Could it happen?
Asteroids the size of Didymos are far rarer than smaller ones, but they exist — and some remain undiscovered.
Professor Collins explains that while smaller asteroids might be deflected with current technology, monsters like Didymos would be nearly impossible to stop without decades of preparation.
The good news? Astronomers believe they have already identified all near-Earth asteroids larger than 0.6 miles (1 km), and none are currently on a collision course with us.
According to a study by scientists at The University of Southampton, it is the heat generated by an asteroid that accounts for nearly 30 per cent of lives lost.
Using computer simulations to pepper Earth with 50,000 asteroids of different sizes, they found that wind blasts and shock waves were likely to kill the most people.
Shock waves from the spike in pressure can rupture internal organs – and the wind blasts carry enough power to hurl human bodies and flatten forests.
In the experimental scenarios, people suffered burns and temporary blindness due to the intense electromagnetic radiation blasting from the meteor.
Senior research assistant Clemens Rumpf said: “If only ten people are affected, then maybe it’s better to evacuate the area.
“But if 1,000,000 people are affected, it may be worthwhile to mount a deflection mission and push the asteroid out of the way.”
Richard Moissl, head of the European Space Agency‘s planetary defence office, is clear: his job is to stop a catastrophe like this before it happens.
He tells The Sun: “Honestly, it’s my very job to prevent something like this from ever happening.”
“Nowadays, there are several big surveys which are dedicated to the search of asteroids, and they are continuously growing in number.
“Once asteroids are detected, they usually need some more measurements of their position to find out where they’re heading, what their orbit is in detail.
“The first step is detection. The second step is the so-called follow-up activities — so we basically refine our knowledge of asteroids. And then a third super important step is, once we have the data, we need to understand it. That is called impact orbit determination and impact risk assessment.
“We know a bit more than 37,000 near-Earth objects at the moment, and for every known object, we track the course it will take and basically almost all the possible courses it could take, because we never measure perfectly.”
And right now, the universe is on our side, Moissl says.
“We know all the asteroids kilometre-size and larger… but I can comfortably say that there is no planet killer on the way to us at least for the next 100 years,” he adds.
Asteroids the size of our hypothetical impactor are considered a “localised threat,” Moissl explains.
“It’s to be made sure that if such a thing ever were to collide with the Earth, that appropriate measures would be in place for the particular area.”
Tracking efforts are ramping up, according to the ESA expert.
“Nowadays, there are several big surveys dedicated to the search for asteroids, and they are continuously growing,” he says.
ESA’s supercomputer, AIS, also runs “up to 100,000 calculations per asteroid” to predict impacts up to a century ahead.
For now, Earth is safe — but the future remains unwritten.
If it veers even slightly in the wrong direction, next time, we may not be so lucky.
Just ask the dinosaurs.
